Ultrasonic cleaner and wet treatment nozzle comprising the same

ABSTRACT

A second housing whose center portion is depressed and whose end portion around the center portion is formed like a visor is arranged around a first housing whose center portion is depressed and whose end portion around the center portion is formed like a visor, and a hollow portion is formed between the first housing and the second housing by sandwiching a packing between the end portions of the housings. Further, degassed water for preventing empty heating is filled in the hollow portion, and an ultrasonic transducer is placed on the surface of the center portion of the first housing. A weight for preventing the vibration of the wall is provided on the wall surface of the second housing. Since the vibration of the wall of the housing is suppressed by the weight, vibration energy returns toward the bottom surface of the center of the housing through water and is radiated from the bottom surface efficiently as ultrasonic waves.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ultrasonic cleaner for irradiatingan object to be cleaned in a cleaning liquid with ultrasonic wavesgenerated from an ultrasonic transducer and to a wet treatment nozzlecomprising the same.

2. Related Art

Heretofore, an ultrasonic shower cleaner 450 as shown in FIG. 21 hasbeen used to clean liquid crystal panels and semiconductor wafers. Inthis ultrasonic shower cleaner 450, a hollow portion 452 for storing acleaning liquid S is formed in the inside of a housing 451 and a liquidfeed port 453 for supplying the cleaning liquid S into the hollowportion 452 is formed in an upper portion of a side wall of the housing451 as shown in the figure. A nozzle 454 for discharging the cleaningliquid S is formed in the lower portion of the housing 451 and anultrasonic transducer 455 is installed on the top surface of the housing451. To clean an object P to be cleaned, this object P is caused to passunder the ultrasonic shower cleaner 450 and the cleaning liquid S ispoured upon the surface of the object P by driving the ultrasonictransducer 455 by means of an unshown ultrasonic wave generator.

However, as the amount of the cleaning liquid is large in this cleaningmethod, a water-saving ultrasonic cleaner 460 shown in FIG. 22 isconceivable. This ultrasonic cleaner 460 has a housing 461 whose centerportion 461 a is depressed and whose end portion 461 b is formed like avisor, an ultrasonic transducer 462 is placed on the surface of thecenter portion of the housing 461, and the object P passing through thecleaning liquid S under the housing 461 is irradiated with ultrasonicwaves to be cleaned by vibrating the ultrasonic transducer 462.

An ultrasonic cleaner 470 shown in FIG. 23 is also conceivable thoughits cleaning method is similar to the above cleaning method. Thisultrasonic cleaner 470 has a first housing 471 whose center portion 471a is depressed and whose end portion 471 b around the center portion 471a is formed like a visor and a second housing 472 surrounding this firsthousing 471, whose center portion 472 a is depressed and whose endportion 472 b around the center portion 472 a is formed like a visor. Apacking 473 is sandwiched between the end portions 471 b and 472 b ofthese housings 471 and 472, and a hollow portion 474 is formed betweenthe first housing 471 and the second housing 472. Further, a liquid forpreventing empty heating, such as water 475, is filled in this hollowportion 474 and an ultrasonic transducer 476 is installed on the surfaceof the center portion of the first housing 471 so that the object Ppassing through the cleaning liquid S under the second housing 472 isirradiated with ultrasonic waves through water 475 in the hollow portion474 to be cleaned by vibrating the ultrasonic transducer 476.

In the case of the ultrasonic cleaner 460 shown in FIG. 22 which is of awater-saving type, the vibration energy of the ultrasonic transducer 462vibrates the bottom surface of the housing 461 and is radiated onto theobject P through the cleaning liquid S. However, it also vibrates thewall surface of the housing 461, resulting in the waste of energy.

In the case of the ultrasonic cleaner 470 shown in FIG. 23, thethickness of the packing slightly differs according to clamping force,whereby the thickness of the hollow portion 474, that is, the depth ofwater filled in the hollow portion 474 differs. In this system that theobject is irradiated with ultrasonic waves through water, sound pressureradiated from the sound wave radiation surface which is the bottomsurface of the center portion of the second housing greatly changesaccording to variations in the depth of water from the relationshipbetween the wavelength of an ultrasonic wave and the depth of water. Inother words, the radiation sound pressure is greatly affected by theclamping force of the packing and lacks stability. When the depth ofwater is not appropriate and radiation sound pressure from theultrasonic wave radiation surface is small, part of energy radiated fromthe ultrasonic transducer which is not used effectively may be used andwasted as energy for vibrating the wall surface of the second housingand may affect other devices by the vibration of the housing.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an ultrasoniccleaner which facilitates the control of ultrasonic wave radiationefficiency and a wet treatment nozzle comprising the same.

According to a first aspect of the present invention, there is providedan ultrasonic cleaner which comprises a housing having an U-shaped crosssection, an ultrasonic transducer placed on the inner surface of theU-shaped portion of the housing and a weight provided on the housing toprevent the vibration of the wall of the housing.

According to this constitution, ultrasonic energy is radiated efficiencyfrom the bottom as ultrasonic waves without leaking to the wall.

The above weight may be placed on the inner wall surface or outer wallsurface if it improves the rigidity of the housing. It may be placed onat least one of the outer wall surface and inner wall surface of thehousing.

The above weight prevents energy from the ultrasonic transducer fromescaping to the housing. If it is placed on the inner bottom surfacewhere the ultrasonic transducer is installed, ultrasonic energy does notleak to the outside from the weight installation portion. Therefore, itmay be placed on the inner bottom surface of the housing in an areawhere vibration caused by the ultrasonic transducer is not prevented.

The above weight may be formed by changing the thickness of the housingitself as means of improving the rigidity of the housing because thesame function can be achieved by making the thickness of a predeterminedportion larger than other portions.

Preferably, the above weight is provided on the entire surface of thewall of the housing to improve the rigidity of the housing and preventenergy from the ultrasonic transducer from propagating to the wall byshifting the characteristic frequency of the wall from the frequency ofvibration input to prevent the resonance of the wall.

According to a second aspect of the present invention, there is provideda wet treatment nozzle which comprises an introduction passage forintroducing a treatment liquid on one side, an exhaust passage forexhausting the treatment liquid after a wet treatment on the other side,and a vibration guide member for guiding the treatment liquid introducedfrom the introduction passage to an object to be treated and wettreating the object while vibrating it, wherein the vibration guidemember is the above-mentioned ultrasonic cleaner.

With this nozzle, the treatment liquid can be supplied onto the surfaceto be treated and the used treatment liquid can be suitably exhaustedthrough the exhaust passage, thereby making it possible to always treatthe surface with a fresh treatment liquid and prevent the surface frombeing contaminated by the used treatment liquid again.

Since the treatment liquid is held in a space between the surface to betreated and the vibration guide member with pressure balance such asinterfacial tension, the surface can be wet treated with the requiredminimum of the treatment liquid and ultrasonic vibration can be providedto the surface to be treated without fail.

Since the ultrasonic cleaner having the weight is used as the vibrationguide member, ultrasonic energy required for a wet treatment is obtainedand an extremely good treatment can be made with the required minimum ofthe treatment liquid.

This wet treatment nozzle is provided with pressure control means ofcontrolling a difference between the pressure of the treatment liquid incontact with the object to be treated and atmospheric pressure toprevent the treatment liquid in contact with the object to be treatedfrom flowing into a passage other than the exhaust passage after a wettreatment. This pressure control means comprises a suction pump providedon a downstream side of the exhaust passage, a liquid feed pump providedon an upstream side of the introduction passage, a pressure sensor fordetecting the pressure of the treatment liquid in contact with theobject to be treated and a controller for controlling the driving of thesuction pump and the liquid feed pump according to a signal from thepressure sensor.

According to a third aspect of the present invention, there is providedan ultrasonic cleaner which comprises a housing having an U-shaped crosssection and a hollow portion therein, an ultrasonic transducer placed onthe inner bottom surface of the inner U-shaped portion of the housing, aliquid for preventing empty heating charged into the hollow portion totransmit vibration from the ultrasonic transducer to the outer bottomsurface of the outer U-shaped portion of the housing, and a weightprovided on the housing to prevent the vibration of the wall of thehousing.

According to this constitution, vibration is prevented by the weightwhen the thickness of the hollow portion, that is, the depth of theliquid for preventing empty heating, for example, water does not matchthe wavelength of an ultrasonic wave according to the fastening degreeof a packing and when energy generated by the ultrasonic transducertries to vibrate the bottom surface of the outer U-shaped portion of thehousing through the liquid for preventing empty heating. Therefore,vibration energy returns toward the bottom of the center portion of thehousing through the liquid for preventing empty heating and is radiatedfrom the bottom efficiently as ultrasonic waves.

The liquid for preventing empty heating is preferably a degassed liquid.By degassing, the flow rate of the liquid for preventing empty heating(circulation for cooling) can be greatly reduced. If the liquid forpreventing empty heating contains many bubbles, the same phenomenon asempty heating may occur.

Since the weight is means of improving the rigidity of the housingitself, it may be placed on the outer wall surface or the inner wallsurface. It is desirably placed on at least one of the outer wallsurface and the inner wall surface forming the above outer U-shapedportion of the housing.

In this case, the weight may be placed on at least one of the outer wallsurface and the inner wall surface forming the inner U-shaped portion ofthe housing to prevent ultrasonic vibration energy from the ultrasonictransducer installed on the inner U-shaped portion from escaping to thewall by increasing the rigidity of the wall of the inner U-shapedportion.

The weight is placed outside an area corresponding to the ultrasonictransducer installed on the inner U-shaped portion on the inner bottomsurface of the outer U-shaped portion to prevent ultrasonic energy fromleaking to the wall from a portion around the inner bottom surface ofthe outer U-shaped portion. The weight is placed outside the ultrasonictransducer installed on the inner U-shaped portion to prevent ultrasonicenergy from leaking to the wall from the inner bottom surface of theinner U-shaped portion. Therefore, the weight may be placed on at leastone of the inner bottom surface of the outer U-shaped portion and thebottom surface of the inner U-shaped portion of the housing in an areawhere vibration caused by the ultrasonic transducer is not prevented.

The weight changes the rigidity of the housing itself. As mean ofattaining this, a new weight maybe added or the thickness of a requiredportion is made appropriate. Therefore, the means may be formed bychanging the thickness of the outer U-shaped portion or the innerU-shaped portion of the housing.

Preferably, the weight is provided on the entire surface of the wall ofthe housing to improve the rigidity of the housing and prevent energyfrom the ultrasonic transducer from propagating to the wall by shiftingthe characteristic frequency of the wall from the frequency of vibrationinput to prevent the resonance of the wall.

Preferably, the housing is constructed such that a second housing whosecenter portion is depressed and whose end portion around the centerportion is formed like a visor is arranged around a first housing whosecenter portion is depressed and whose end portion around the centerportion is formed like a visor, and a hollow portion is formed betweenthe first housing and the second housing by sandwiching a packingbetween the end portions of the housings.

In the housing, an appropriate liquid is placed in this hollow portion,thereby making it possible to prevent the breakage of the ultrasonictransducer caused by heating without a wet treatment liquid under thehousing. When the wet treatment liquid is located below the housing,sufficient ultrasonic energy can be propagated to the wet treatmentliquid.

According to a fourth aspect of the present invention, there is providedan ultrasonic cleaner in which the packing is made of an elastic memberhaving a through hole in the center, the first housing and the secondhousing are made of a plate member, the elastic member is sandwichedbetween the visor-like end portion of the first housing and thevisor-like end portion of the second housing with a bolt penetrating theend portions, and the thickness of the packing can be changed byadjusting the fastening degree of the bolt.

According to this constitution, the thickness of the elastic membersandwiched between the visor-like end portion of the first housing andthe visor-like end portion of the second housing can be adjusted bycontrolling the fastening degree of the bolt, thereby making it easy toadjust the radiation strength of ultrasonic waves.

According to a fifth aspect of the present invention, there is provideda wet treatment nozzle which comprises an introduction passage forintroducing a treatment liquid on one side, an exhaust passage forexhausting the treatment liquid after a wet treatment on the other sideand a vibration guide member, interposed between the introductionpassage and the exhaust passage, for guiding the treatment liquidintroduced from the introduction passage to an object to be treated andwet treating the object while vibrating it, wherein the above vibrationguide member is the above-mentioned ultrasonic cleaner of the presentinvention.

With this nozzle, the treatment liquid can be supplied onto the surfaceto be treated and the used treatment liquid can be suitably exhaustedthrough the exhaust passage, thereby making it possible to always treatthe surface with a fresh treatment liquid and prevent the surface frombeing contaminated by the used treatment liquid again.

Since the treatment liquid is held in a space between the surface to betreated and the vibration guide member with pressure balance such asinterfacial tension, the surface can be wet treated with the requiredminimum of the treatment liquid and ultrasonic vibration can be appliedto the surface to be treated without fail.

In addition, even if the treatment liquid in the space between theultrasonic vibration guide member and the treatment surface runs short,a liquid for preventing empty heating is existent in the space betweenthe ultrasonic transducer and the ultrasonic vibration guide member,thereby making it possible to prevent the empty heating of theultrasonic transducer without fail.

This wet treatment nozzle is also provided with pressure control meansof controlling the difference between the pressure of the treatmentliquid in contact with the object to be treated and atmospheric pressureto prevent the treatment liquid in contact with the object from flowingto the outside of the exhaust passage after the wet treatment.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1A is a perspective view of a first embodiment of an ultrasoniccleaner according to the present invention and FIG. 1B is an enlargedlongitudinal sectional view cut on line Ib-Ib of FIG. 1A;

FIG. 2 is a longitudinal sectional view showing that an object to becleaned is cleaned by the ultrasonic cleaner shown in FIGS. 1A and 1B;

FIG. 3 is a longitudinal sectional view of a second embodiment of theultrasonic cleaner according to the present invention;

FIG. 4 is a longitudinal sectional view of a third embodiment of theultrasonic cleaner according to the present invention;

FIG. 5 is a longitudinal sectional view of a fourth embodiment of theultrasonic cleaner according to the present invention;

FIG. 6 is a longitudinal sectional view of a fifth embodiment of theultrasonic cleaner according to the present invention;

FIG. 7 is a longitudinal sectional view of a sixth embodiment of theultrasonic cleaner according to the present invention;

FIG. 8 is a longitudinal sectional view of a seventh embodiment of theultrasonic cleaner according to the present invention;

FIG. 9 is a longitudinal sectional view of an eighth embodiment of theultrasonic cleaner according to the present invention;

FIG. 10A is a perspective view of a tenth embodiment of the ultrasoniccleaner according to the present invention and FIG. 10B is an enlargedlongitudinal sectional view cut on line Xb-Xb of FIG. 10A;

FIG. 11A is a perspective view of an eleventh embodiment of theultrasonic cleaner according to the present invention and FIG. 11B is anenlarged longitudinal sectional view cut on line XIb-XIb of FIG. 11A;

FIG. 12A is a perspective view of an embodiment of a wet treatmentnozzle according to the present invention and FIG. 12B is an enlargedlongitudinal sectional view cut on line XIIb-XIIb of FIG. 12A;

FIG. 13 is a longitudinal section view showing that an object to becleaned is cleaned by the wet treatment nozzle shown in FIGS. 12A and12B;

FIG. 14A is a perspective view of a first embodiment of other ultrasoniccleaner according to the present invention and FIG. 14B is an enlargedlongitudinal sectional view cut on line XIVb-XIVb of FIG. 14A;

FIG. 15 is a longitudinal sectional view showing that an object to becleaned is cleaned by the ultrasonic cleaner shown in FIGS. 14A and 14B;

FIG. 16 is a longitudinal sectional view of a second embodiment of theother ultrasonic cleaner according to the present invention;

FIG. 17 is a longitudinal sectional view of a third embodiment of theother ultrasonic cleaner according to the present invention;

FIG. 18A is a perspective view of a fourth embodiment of the otherultrasonic cleaner according to the present invention and FIG. 18B is anenlarged longitudinal sectional view cut on line XVIIIb-XVIIIb of FIG.18A;

FIG. 19A is a perspective view of an embodiment of other wet treatmentnozzle according to the present intention and FIG. 19B is an enlargedlongitudinal sectional view cut on line XIXb-XIXb of FIG. 19A;

FIG. 20 is a sectional view showing that an object to be cleaned iscleaned by the wet treatment nozzle shown in FIGS. 19A and 19B;

FIG. 21 is a longitudinal sectional view of an ultrasonic shower cleanerof the prior art;

FIG. 22 is a longitudinal sectional view of a water saving ultrasoniccleaner of the prior art; and

FIG. 23 is a longitudinal sectional view of a water saving ultrasoniccleaner of a double tank system of the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of an ultrasonic cleaner according to the presentinvention will be described hereinunder with reference to theaccompanying drawings.

FIGS. 1A and 1B show the first embodiment of an ultrasonic cleaneraccording to the present invention.

This ultrasonic cleaner 10 has a tank-like first housing 11 whose centerportion 11 a is depressed and whose end portion 11 b around the centerportion 11 a is formed like a visor and a tank-like second housing 12surrounding this first housing 11, whose center portion 12 a isdepressed and whose end portion 12 b around the center portion 12 a isformed like a visor. A packing 13 is sandwiched between the end portions11 b and 12 b of the housings 11 and 12 and a hollow portion 14 isformed between the first housing 11 and the second housing 12. Thepacking 13 is provided at the entire periphery between the end portions11 b and 12 b of the first and second housings 11 and 12 and fastened bya plurality of bolts 18 and a plurality of nuts 19.

Water 15 which has been degassed as a liquid for preventing emptyheating is charged into the hollow portion 14 formed between the firsthousing 11 and the second housing by sandwiching the packing 13therebetween. Water 15 is filled in at least the space between thecenter portion 11 a (bottom surface) of the first housing 11 and thecenter portion 12 a (bottom surface) of the second housing 12. Further,an ultrasonic transducer 16 is installed on the surface of the centerportion 11 a of the first housing 11 and an object to be cleaned (notshown) passing through a cleaning liquid (not shown) under a radiationsurface having the width L of the second housing 12 is irradiated withultrasonic waves through water 15 in the hollow portion 14 by vibratingthe ultrasonic transducer 16 to be cleaned.

A ring-shaped weight 17 is provided on the entire surface of the outerlower portion of the wall 12 c of the second housing 12.

A function and effect obtained by providing this weight 17 will bedescribed hereinunder. As shown in FIG. 2, the center portion 12 a ofthe second housing 12 of the ultrasonic cleaner 10 is immersed in thecleaning liquid S so that the object P to be cleaned passes under theultrasonic cleaner 10. The ultrasonic transducer 16 is vibrated by anunshown ultrasonic wave generator to irradiate the object P passingunder the radiation surface having the width L of the second housing 12with ultrasonic waves through water 15 in the hollow portion 14 to cleanit.

The hollow portion 14 is formed by sandwiching the packing 13 betweenthe end portions 11 b and 12 b of the first housing 11 and the secondhousing 12 and fixing it by fastening. When the thickness of the hollowportion 14, that is, the depth of water 15 does not agree with thewavelength of an ultrasonic wave according to the fastening degree ofthe packing 13, radiation sound pressure from the sound wave radiationsurface which is the bottom surface of the center portion 12 a of thesecond housing 12 decreases. Although a component equivalent to areduction in vibration energy radiated from the ultrasonic transducer 16is used to vibrate the wall surface 12 c of the second housing 12, thevibration of the wall surface 12 c is suppressed by the weight 17.Therefore, the vibration energy returns toward the bottom surface 12 aof the second housing 12 through water 15 to be radiated from the bottomsurface 12 a as an ultrasonic wave. As a result, energy generated fromthe ultrasonic transducer 16 can be irradiated onto the object to becleaned efficiently irrespective of the fastening degree of the packing13.

Thus, the weight 17 is provided to control changes in radiation soundpressure generated by changes in the depth of water which is affected bythe fastening amount of the packing 13 to an almost fixed value.

The second to eighth embodiments of the ultrasonic cleaner according tothe present invention will be described hereinunder with reference toFIGS. 3 to B. Another weight is added to the weight 17 of the firstembodiment shown in FIGS. 1A and 1B in these embodiments. The samemembers as those in FIGS. 1A and 1B are given the same reference symbolsand their descriptions are omitted.

The second embodiment shown in FIG. 3 is an ultrasonic cleaner 20 inwhich a second ring-shaped weight 21 is provided on the entire surfaceof the inner lower portion of the wall 12 c of the housing 12. In thesecond embodiment, the weight 17 can be made smaller than that of thefirst embodiment by providing the second weight 21, whereby the width ofthe ultrasonic cleaner comprising the housing 12 and the weight 17 canbe reduced. Also, the polishing of the under surface of the weight 17can be carried out more easily.

The third embodiment shown in FIG. 4 is an ultrasonic cleaner 30 inwhich a third ring-shaped weight 31 is provided on the entire surface ofthe inner lower portion of the wall 11 c of the first housing 11. Thethird embodiment can prevent ultrasonic energy radiated from theultrasonic transducer 16 provided in the first housing 11 frompropagating to the wall 11 c more than the first embodiment by providingthe third weight 31, whereby the proportion of ultrasonic energypropagating to the side of the liquid for preventing empty heating isgreatly increased and the radiation of ultrasonic energy from the outerbottom surface 12 a can be enhanced.

The fourth embodiment shown in FIG. 5 is an ultrasonic cleaner 40 inwhich a fourth ring-shaped weight 41 is provided on the entire surfaceof the outer lower portion of the wall 11 c of the first housing 11. Thefourth embodiment obtains almost the same effect as that of the thirdembodiment by providing the fourth weight 41.

The fifth embodiment shown in FIG. 6 is an ultrasonic cleaner 50 inwhich a fifth ring-shaped weight 51 is provided on the entire surface ofthe inner peripheral portion of the bottom 12 a of the second housing12. In the fifth embodiment, the weight 17 can be made smaller than thatof the first embodiment, whereby the width of the ultrasonic cleanercomprising the housing 12 and the weight 17 can be reduced and thepolishing of the under surface of the weight 17 can be carried outbetter, thereby making it possible to reduce production cost.

The sixth embodiment shown in FIG. 7 is an ultrasonic cleaner 60 inwhich a sixth ring-shaped weight 61 is provided on the entire surface ofthe inner peripheral portion of the bottom 11 a of the first housing 11.The sixth embodiment obtains almost the same effect as that of the thirdembodiment by providing the sixth weight 61.

The seventh embodiment shown in FIG. 8 is an ultrasonic cleaner 70 inwhich a seventh ring-shaped weight 71 is provided on the entire surfaceof the inner lower portion of the wall 12 c of the second housing 12 andan eighth ring-shaped weight 72 is also provided on the entire surfaceof the inner peripheral portion of the bottom 12 a of the second housing12. In the seventh embodiment, the weight 17 can be made smaller thanthat of the fifth embodiment as compared with the first embodiment byproviding the seventh weight 71 and the eighth weight 72, whereby thewidth of the total housing can be reduced, the weight 17 and a portionnear the outer depressed portion 12 can be polished better than thefifth embodiment, and the stability of a wet treatment can be increased.

The eighth embodiment shown in FIG. 9 is an ultrasonic cleaner 80 inwhich a ninth ring-shaped weight 81 is provided on the entire surface ofthe inner lower portion of the wall 11 c of the first housing 11, atenth ring-shaped weight 82 is provided on the entire surface of theouter lower portion of the wall 11 c of the first housing 11 and aneleventh ring-shaped weight 83 is provided on the entire surface of theinner peripheral portion of the bottom 11 a of the first housing 11. Inthe eighth embodiment, ultrasonic energy can be irradiated from thebottom 12 a of the second housing 12 efficiently almost like the thirdembodiment by providing the ninth weight 81, the tenth weight 82 and theeleventh weight 83.

Further, the ninth and tenth embodiments of the ultrasonic cleaneraccording to the present invention will be described with reference toFIGS. 10 and 11, respectively. In these embodiments, the weight 17 ofthe first embodiment shown in FIGS. 1A and 1B is replaced by otherweights which are placed in the first housing 11 or the second housing12. The same members as those in FIGS. 1A and 1B are given the samereference symbols and their descriptions are omitted.

The ninth embodiment shown in FIGS. 10A and 10B is an ultrasonic cleaner90 in which a twelfth ring-shaped weight 91 is provided on the entiresurface of the inner lower portion of the wall 12 c of the secondhousing 12. In the ninth embodiment, the width of a treatment nozzle isdetermined by the size of the second housing 12 unlike the firstembodiment because the weight 17 is nonexistent and does not increaseand the polishing of the outer wall surface and the outer bottom surfaceof the second housing 12 can be carried out extremely easily, therebymaking it easy to manufacture a wet treatment nozzle.

The tenth embodiment shown in FIGS. 11A and 11B is an ultrasonic cleaner100 in which a thirteenth ring-shaped weight 101 is provided on theentire surface of the inner peripheral portion of the bottom 12 a of thesecond housing 12. The tenth embodiment can obtain almost the sameeffect as that of the ninth embodiment by providing the thirteenthweight 101.

A preferred embodiment of a wet treatment nozzle according to thepresent invention which comprises the above ultrasonic cleaner will bedescribed hereinunder with reference to FIGS. 12A and 12B.

This wet treatment nozzle 110 comprises an introduction passage 111 forintroducing a treatment liquid (not shown) on one side, an exhaustpassage 112 for exhausting the treatment liquid L after a wet treatmenton the other side, and a vibration guide member 113, interposed betweenthe introduction passage 111 and the exhaust passage 112, for guidingthe treatment liquid introduced from the introduction passage 111 to anobject to be treated (not shown) and wet treating the object whilevibrating it. The ultrasonic cleaner 10 shown in FIGS. 1A and 1B is usedas the vibration guide member 113. Therefore, the same members as thoseof FIGS. 1A and 1B are given the same reference symbols in FIGS. 12A and12B and their descriptions are omitted.

In FIGS. 12A and 12B, an introduction passage frame 114 having theintroduction passage 111 formed therein is made of a stainlesssteel-metal plate having an L-shaped cross section and its bottom 114 ais made flush or almost flush with the bottom 12 a of the vibrationguide member. The introduction passage frame 114 has an introductiontube 114 b extending obliquely upward in the center portion in alongitudinal direction and its wall 114 c is connected to the weight 17provided on the outer surface of the wall 12 c of the vibration guidemember by welding. This connection may be carried out with a bolt and anut.

Similarly, the exhaust passage frame 115 having the exhaust passage 112formed therein is made of a stainless steel metal plate having anL-shaped cross section and its bottom 115 a is made flush or almostflush with the bottom 12 a of the vibration guide member. The exhaustpassage frame 115 has an exhaust tube 115 b extending obliquely upwardin the center portion in a longitudinal direction and its wall 115 c isconnected to the weight 17 provided on the outer surface of the wall 12c of the vibration guide member by welding. This connection may becarried out with a bolt and a nut.

This wet treatment nozzle 110 is provided with a pressure controller(not shown) for controlling the difference between the pressure of thetreatment liquid in contact with the object to be treated andatmospheric pressure so that the treatment liquid in contact with theobject does not flow to the outside of the exhaust passage after the wettreatment. This wet treatment nozzle 110 is also provided with apositioning unit (not shown) for maintaining a predetermined spacebetween the vibration guide member 113 and the object and holding thetreatment liquid in the space.

A wet treatment method using this wet treatment nozzle will be describedwith reference to FIG. 13.

The treatment liquid L, for example, ultra pure water, electrolyzed ionwater, ozone water or hydrogen water is supplied to the object P to betreated through the introduction passage 111 while the object P to betreated and the wet treatment nozzle 110 are moved in directions A and Brelative to each other, respectively, and the treatment liquid L isexhausted from above the object P without contacting a portion otherthan the portion to which the treatment liquid L is supplied bycontrolling the difference between the pressure of the treatment liquidL in contact with the object P and atmospheric pressure by means of thepressure controller (not shown).

The wet treatment nozzle shown in FIG. 12 comprises the ultrasoniccleaner shown in FIGS. 1A and 1B as the vibration guide member. The wettreatment nozzle of the present invention is not limited to this and theultrasonic cleaners shown in FIGS. 3 to 11 may be used.

A description is subsequently given of preferred embodiments of otherultrasonic cleaner according to the present invention.

As shown in FIGS. 14A and 14B, an ultrasonic cleaner 200 which is thefirst embodiment of the other ultrasonic cleaner comprises a tank-likehousing 201 whose center portion 201 a is depressed and whose endportion 201 b around the center portion 201 a is formed like a visor, anultrasonic transducer 216 installed on the surface of the center portion201 a of the housing and a ring-shaped weight 217 provided on the entiresurface of the outer lower portion of the wall 201 c of the housing.

This ultrasonic cleaner 200 irradiates an object to be treated passingthrough a cleaning liquid (not shown) below the radiation surface havingthe width L2 of the housing 201 with ultrasonic waves by vibrating theultrasonic transducer 216 to clean it.

A function and effect obtained by providing this weight 217 will bedescribed hereinunder. As shown in FIG. 15, the center portion 201 a ofthe housing 201 of the ultrasonic cleaner 200 is immersed in thecleaning liquid S and the object P passes below the ultrasonic cleaner216. The ultrasonic transducer 216 is vibrated by an unshown ultrasonicwave generator to irradiate the object P passing below the radiationsurface having the width L2 of the housing 201 with ultrasonic waves toclean it. During this treatment, ultrasonic energy radiated from theultrasonic transducer 216 can be prevented from propagating to thehousing 201 and the upper portion of the weight 217 extremely well dueto the existence of the weight 217, whereby the ultrasonic energypropagates to the cleaning liquid S from the bottom 201 a to clean theobject well.

The second and third embodiments of the other ultrasonic cleaneraccording to the present invention will be described with reference toFIG. 16 and FIG. 17. In these embodiments, another weight is provided inaddition to the weight 217 of the first embodiment of the otherultrasonic cleaner shown in FIGS. 14A and 14B. The same constituentmembers as those shown in FIGS. 14A and 14B are given the same referencesymbols and their descriptions are omitted.

The second embodiment of the other ultrasonic cleaner shown in FIG. 16is an ultrasonic cleaner 230 in which a second ring-shaped weight 218 isprovided on the entire surface of the inner lower portion of the wall201 c of the housing 201. In the second embodiment, the weight 217 canbe made smaller than that of the first embodiment by providing theweight 218, whereby the polishing of the outer wall surface and theouter bottom surface of the housing 201 including the weight 217 iscarried out very easily and the stability of the nozzle is improved. Theeffect of propagating ultrasonic energy to the cleaning liquideffectively can be made the same as that of the first embodiment shownin FIGS. 14A and 14B.

The third embodiment of the other ultrasonic cleaner shown in FIG. 17 isan ultrasonic cleaner 240 in which a third ring-shaped weight 219 isfurther provided on the entire surface of the inner peripheral portionof the bottom 201 a of the housing 201 of the cleaner shown in FIG. 16.In this third embodiment, the weight 217 can be made much smaller thanthat of the first embodiment shown in FIGS. 14A and 14B by providing theweights 218 and 219. Thereby, the polishing of the outer wall surfaceand the outer bottom surface of the housing can be carried out moreeasily than the second embodiment and the stability of the wet treatmentnozzle can be improved.

Further, the fourth embodiment of the other ultrasonic cleaner accordingto the present invention will be described with reference to FIGS. 18Aand 18B. In this embodiment, the weight 217 in the first embodimentshown in FIGS. 14A and 14B is eliminated and another weight is providedon the housing 201 instead. The same constituent members as those ofFIGS. 14A and 14B are given the same reference symbols and theirdescriptions are omitted.

The fourth embodiment shown in FIGS. 18A and 18B is an ultrasoniccleaner 250 in which a fourth ring-shaped weight 220 is provided on theentire surface of the inner peripheral portion of the bottom 201 a ofthe housing 201. In this embodiment, as there is only the weight 220 andnothing else is added to the outer wall surface of the housing 201compared with the first embodiment shown in FIGS. 14A and 14B, thepolishing of the outer wall surface and the outer bottom surface of thehousing 201 can be carried out the most easily and the stability of thewet treatment nozzle can be greatly improved.

An embodiment of the wet treatment nozzle of the present invention usingthe above ultrasonic cleaner will be described with reference to FIGS.19A and 19B.

This wet treatment nozzle 310 comprises an introduction passage 311 forintroducing a treatment liquid (not shown) on one side, an exhaustpassage 312 for exhausting the treatment liquid L after a wet treatmenton the other side, and a vibration guide member 313, interposed betweenthe introduction passage 311 and the exhaust passage 312, for guidingthe treatment liquid introduced from the introduction passage 311 to anobject to be treated (not shown) and wet treating the object whilevibrating it. The ultrasonic cleaner 230 shown in FIG. 16 is used as thevibration guide member 313. Therefore, the same members as those of FIG.16 are given the same reference symbols in FIGS. 19A and 19B and theirdescriptions are omitted.

In FIGS. 19A and 19B, an introduction passage frame 314 having theintroduction passage 311 formed therein is made of a stainless steelmetal plate having an L-shaped cross section and its bottom 314 a ismade flush or almost flush with the bottom 201 a of the vibration guidemember. The introduction passage frame 314 has an introduction tube 314b extending obliquely upward in the center portion in a longitudinaldirection and its wall 314 c is connected to the weight 217 provided onthe outer surface of the wall 201 c of the vibration guide member bywelding. This connection may be carried out with a bolt and a nut.

Similarly, the exhaust passage frame 315 having the exhaust passage 312formed therein is made of a stainless steel metal plate having anL-shaped cross section and its bottom 315 a is made flush or almostflush with the bottom 201 a of the vibration guide member. The exhaustpassage frame 315 has an exhaust tube 315 b extending obliquely upwardin the center portion in a longitudinal direction and its wall 315 c isconnected to the weight 217 provided on the outer surface of the wall201 c of the vibration guide member by welding. This connection may becarried out with a bolt and a nut.

This wet treatment nozzle 300 is provided with a pressure controller(not-shown) for controlling the difference between the pressure of thetreatment liquid in contact with the object to be treated andatmospheric pressure so that the treatment liquid in contact with theobject does not flow to the outside of the exhaust passage after the wettreatment. This wet treatment nozzle 300 is also provided a positioningunit (not shown) for maintaining a predetermined space between thevibration guide member 313 and the object and holding the treatmentliquid in the space.

A wet treatment method using this wet treatment nozzle will be describedwith reference to FIG. 20.

The treatment liquid L, for example, ultra pure water, electrolyzed ionwater, ozone water or hydrogen water is supplied to the object P to betreated through the introduction passage 311 while the object P to betreated and the wet treatment nozzle 300 are moved in directions C and Drelative to each other, respectively, and the treatment liquid L isexhausted from above the object P without contacting a portion otherthan the portion to which the treatment liquid L is supplied bycontrolling the difference between the pressure of the treatment liquidL in contact with the object P and atmospheric pressure by means of thepressure controller (not shown).

The wet treatment nozzle shown in FIGS. 19A and 19B comprises theultrasonic cleaner shown in FIG. 16 as the vibration guide member. Thewet treatment nozzle of the present invention is not limited to this andthe ultrasonic cleaners shown in FIGS. 14, 17 and 18 may be used.

As described above, according to the ultrasonic cleaner of the presentinvention, since the vibration of the wall of the housing is suppressedby the weight, vibration energy returns toward the bottom of the centerportion of the housing through the liquid for preventing empty heatingor the housing itself and is radiated from the bottom as ultrasonicwaves efficiently. Therefore, an ultrasonic cleaner capable of adjustingthe radiation efficiency of ultrasonic waves easily and a wet treatmentnozzle comprising the same are obtained.

1. A wet treatment nozzle comprising: an ultrasonic cleaner comprising afirst housing, a second housing, and a hollow portion between the firstand second housing, an ultrasonic transducer placed on an interiorbottom surface of the first housing, and a weight provided on the secondhousing; an introduction passage for introducing a treatment liquid onan exterior side of the ultrasonic cleaner; an exhaust passage whichexhausts the treatment liquid on an other exterior side of theultrasonic cleaner after a wet treatment of an object to be treated, theexhaust passage exhausting the treatment liquid that wet treated theobject; wherein the ultrasonic cleaner includes a flow path along anexterior side of the second housing between the introduction passage andthe exhaust passage that guides the treatment liquid to wet treat theobject to be treated, such that the treatment liquid is exposed toatmosphere between the second housing and the object to be treated,wherein the weight minimizes propagation of energy from the ultrasonictransducer to a wall of the second housing by shifting thecharacteristic frequency of the wall of the second housing; and apressure controller operable to maintain a difference between a pressureof the treatment liquid in contact with the object to be treated and anatmospheric pressure, so that the treatment liquid in contact with theobject does not flow to the outside of the flow path.
 2. The wettreatment nozzle according to claim 1, wherein the weight is provided onat least one of an exterior wall surface or an interior wall surface ofthe weighted housing in the ultrasonic cleaner.
 3. The wet treatmentnozzle according to claim 1, wherein the weight is provided on theinterior bottom surface of the weighted housing in an area wherevibration caused by the ultrasonic transducer is not prevented in theultrasonic cleaner.
 4. The wet treatment nozzle according to claim 1,wherein the weight is formed by changing the thickness of the weightedhousing in the ultrasonic cleaner.
 5. The wet treatment nozzle accordingto claim 1, wherein the weight is provided on the entire surface of thewall of the weighted housing in the ultrasonic cleaner.
 6. The wettreatment nozzle according to claim 1, wherein the first and secondhousings have a U shaped cross-section.
 7. The wet treatment nozzleaccording to claim 1, wherein the shifting of the characteristicfrequency of the wall of the second housing minimizes a resonance of thewall of the second housing.
 8. The wet treatment nozzle according toclaim 1, wherein the flow path is configured such that only thetreatment liquid contacts the object to be treated between theintroduction passage and the exhaust passage.
 9. The wet treatmentnozzle according to claim 1, wherein the ultrasonic cleaner guides thetreatment liquid introduced from the introduction passage such thatfresh treatment liquid is always supplied to the object to be treated.10. The wet treatment nozzle according to claim 1, wherein the weightcomprises a ring-shaped weight disposed around the second housing.
 11. Awet treatment nozzle comprising: an ultrasonic cleaner comprising a ahousing, an ultrasonic transducer placed on a bottom surface of thehousing, and a weight on the housing; an introduction passage associatedwith a first frame member, the introduction passage configured tointroduce a treatment liquid on a first side of the ultrasonic cleaner;and an exhaust passage associated with a second frame member, theexhaust passage configured to exhaust the treatment liquid on a secondside of the ultrasonic cleaner after a wet treatment of an object to betreated, wherein the ultrasonic cleaner, while vibrating, is configuredto guide the treatment liquid along a bottom surface of the housing towet treat the object, and wherein the weight separates the first andsecond frame members from the housing and is configured to minimizepropagation of energy from the ultrasonic transducer to the housing andto the frame members by shifting the characteristic frequency of thehousing.
 12. The wet treatment nozzle according to claim 11, wherein thehousing and the first and second frame members cooperate to define aflow path, the flow path configured such that only the treatment liquidcontacts the object to be treated between the first frame member and thesecond frame member.
 13. The wet treatment nozzle according to claim 12further comprising a pressure controller operable to maintain adifference between a pressure of the treatment liquid in contact withthe object and an atmospheric pressure, so that the treatment liquid incontact with the object does not flow to the outside of the flow path.14. The wet treatment nozzle according to claim 11, wherein the weightcomprises a ring-shaped weight disposed around the housing.